Step 1: To install a load balancer (marathon-lb) on the public agents of the DC/OS cluster navigate to the DC/OS dashboard and click the 'Universe' tab.
Step 2: Scroll down until you find the marathon-lb package and click on the package to install it.
Step 3: The marathon-lb package is a configuration of HAProxy that uses Marathon state. Click on 'Install Package' to start the installation process of marathon-lb.
Step 4: Click on the 'Advanced Installation' link to review the default configuration of marathon-lb.
Step 5: review the marathon-lb default values of the configuration properties of marathon-lb.
Step 6: scroll down to review the remaining marathon-lb default values and then click the 'Review and Install' button.
Step 7: Review the configuration of marathon-lb one more time then click the 'Install' button to install marathon-lb on your DC/OS cluster.
Step 8: Close the 'Success!' acknowledgement dialog by clicking the checkmark button.
Step 9: To verify that marathon-lb was successfully installed navigate to the DC/OS Services tab and open the Marathon UI.
Step 10: In the Marathon UI we can see a new application listed named 'marathon-lb-default'.
Step 11: Clicking on the marathon-lb app in the listing we can see more detailed configuration including the range of ports that HAProxy has pre-configured including ports 10000-10100. These ports are where we will assign any applications that run within the DC/OS cluster that need to have the ability to be accessed externally from the DC/OS cluster.
Step 12: There are a few additional steps required to open up load balancer ports on Microsoft Azure, see instructions here.
Congratulations: You now have a load balancer (marathon-lb) installed on public agents are ready to load balance application requests on the DC/OS cluster. Next, we will walk through how to Schedule the Map Visualization.